How to print the date and time in the footer of a score?

[Charles Cave]

I would like to print the date and time in the footer of the score so I can
tell which of two printed copies is the most recent.

I searched the Lilypond documentation (PDF) (I used version 2.8.3)
for the word date and could not find any mention.  

Printing dates and times in Word processing documents is a standard
feature and I would like to do the same with Lilypond.

By the way, I started using SubVersion to manage my scores under version
control. 

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Charles Cave
Sydney, NSW, Australia
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